Ingestion of chlorinated water has no effect upon indicators of cardiovascular disease in pigeons
Related Experiment Videos
1Institute of Environmental Medicine, New York University Medical Center, New York 10016.
Insights
This study found no evidence that chlorinated drinking water affects cholesterol levels or arteriosclerotic plaque development in White Carneau pigeons. Previous claims of such effects in this cardiovascular disease model were not replicated.
Area of Science:
- Cardiovascular Science
- Toxicology
- Animal Models in Disease Research
Background:
- Cardiovascular disease (CVD) is a leading cause of death in the US, with arteriosclerotic plaque being a key lesion.
- White Carneau (WC) pigeons are a validated animal model for studying CVD and atherosclerosis.
- Previous research in 1986 suggested chlorinated (Cl) water may directly impact lipid levels and plaque development in young WC pigeons.
Purpose of the Study:
- To investigate the potential direct effects of chlorinated drinking water on lipid profiles and arteriosclerotic plaque formation in young WC pigeons.
- To replicate and critically evaluate previous findings suggesting a link between chlorinated water consumption and atherosclerosis development.
Main Methods:
- Young male WC pigeons were exposed to 2 ppm or 15 ppm chlorinated water for 3 months.
- Pigeons were fed a normocholesterolemic (NC) diet with reduced calcium (Ca2+) levels.
- Blood lipid levels (cholesterol, triglycerides, LDL) and plaque size were measured and compared to control groups.
Main Results:
- Exposure to chlorinated water at 2 ppm or 15 ppm did not significantly alter body weight, cholesterol, triglyceride, or LDL levels in WC pigeons.
- No significant increase in arteriosclerotic plaque size was observed in pigeons drinking chlorinated water compared to controls after 3 months.
- The study failed to replicate the findings of earlier reports suggesting a direct effect of chlorinated water on lipid metabolism and atherosclerosis in this model.
Conclusions:
- Drinking chlorinated water does not appear to affect circulating lipid levels or the development of arteriosclerotic plaques in young White Carneau pigeons under the tested conditions.
- The findings contradict previous reports and suggest that chlorinated water may not be a significant risk factor for atherosclerosis in this animal model.
- Further research may be needed to fully elucidate the complex factors involved in atherosclerosis development and the potential role of water contaminants.
Abstract:
Cardiovascular disease (CVD) accounts for nearly half the deaths, yearly, in the United States. The arterio(athero)sclerotic plaque is the principal lesion of CVD. The White Carneau (WC) pigeon is an animal model that has been employed extensively for studying CVD. Cholesterol (CHOL) feeding aggravates atherosclerosis in WC pigeons greater than 2 years old. In 1986, two reports appeared from a single laboratory claiming a direct effect of drinking chlorinated (Cl) water upon lipid levels and plaque development in young (less than 1 year) WC pigeons. These are the only reports of such direct effects, to date. Three months' exposure to 2 ppm or 15 ppm Cl in the drinking water, resulted in increased circulating CHOL levels in young male WC pigeons fed a normocholesterolemic (NC) diet in which Ca2+ levels were reduced. In addition, at both Cl concentrations there was a significant increase in plaque size, compared to controls. Pigeons in the 2 ppm group also exhibited elevated low density lipoprotein (LDL) levels after 3 months on the NC diet. These findings, if extrapolated to man, could have considerable public health consequences, since nearly 200 million people in the United States drink Cl water. We have carried out a similar set of studies but with strikingly different results. We used the same suppliers of pigeons and feed as did the authors of the 1986 reports and followed their approach where possible. Six month-old male WC pigeons drank water with 2 ppm or 15 ppm Cl (pH 8.5) and ate a NC diet with Ca2+ reduced to 80% of normal. At both 1 and 3 months, body weight, CHOL, triglyceride and LDL levels were unaffected by drinking Cl water. There was also no effect of Cl water on plaque size after 3 months. Thus, we found no evidence that drinking chlorinated water has any effect upon circulating lipid levels or upon the development of arteriosclerotic plaques, in this animal model.